Volume Shadow Copy Services (VSS) is a great technology which can be useful in many ways. Your Backup-SW may already be using this technology to do the system-state backups without you knowing it (e.g. even NTbackup leverages VSS).
You're likely talking about using the Shadow Copy Restore Feature (aka "Previous Versions") and I agree that it's a great thing to use. Beware that it doesn't replace your normal backup, but it will either reduce a user's dependency on admins (if you install the previous versions client on the users system and teach them how to use it) or it allows the admins/helpdesk to restore files quickly _without_ going back to tape. As far as I know, you can currently only use the Shadow Copy Restore Feature for directly attached storage, since it leverages the built-in VSS software-provider. I don't think it works with any VSS HW-providers => which means you can' use Shadow Copy Restore if you store your files on a SAN (if someone has some newer info on this, I'd be happy to hear). rgd. the defrag issue, see Q312067 "Shadow Copies May Be Lost When You Defragment a Volume" - here are the most important details: The System Shadow Copy provider uses a copy-on-write mechanism that operates at a 16-KB block level. This is independent of the file system's cluster allocation unit size. If the file system's cluster size is smaller than 16 KB, the System Shadow Copy provider cannot easily determine that disk defragmentation I/O is different from typical write I/O, and performs a copy-on-write operation. This might cause the Shadow Copy storage area to grow very quickly. If the storage area reaches its user-defined limit, the oldest shadow copies are deleted first. => this can be fixed, if the cluster size on the volume is changed from the default 4k to 16k (or larger) /Guido -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Robert Mezzone Sent: Tuesday, October 19, 2004 12:18 AM To: '[EMAIL PROTECTED]' Subject: Re: [ActiveDir] Shadow Copy There is an article in TechNet about formatting the drive with a certain cluster size, if you don't and you defrag the drive, all your snapshots are deleted during defrag. I've been using it for a year now wo any problems. I store all the snapshots on a dedicated set of mirrored drives. Between shadow copy and a long retention time for undelete, I have't restored anything from tape in a very long time. Robert -----Original Message----- From: [EMAIL PROTECTED] <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] <[EMAIL PROTECTED]> Sent: Mon Oct 18 15:41:39 2004 Subject: [ActiveDir] Shadow Copy My company is thinking of instituting Shadow Copy. Any advice would be appreciated. What are the approximate costs ? List info : http://www.activedir.org/mail_list.htm List FAQ : http://www.activedir.org/list_faq.htm List archive: http://www.mail-archive.com/activedir%40mail.activedir.org/ List info : http://www.activedir.org/mail_list.htm List FAQ : http://www.activedir.org/list_faq.htm List archive: http://www.mail-archive.com/activedir%40mail.activedir.org/
